U01A5Lost Communication With Hybrid/EV Battery Interface Control Module F
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U01A5 says the battery controller no longer receives data from interface module F. Once such a board drops out, the cells it covers are unsupervised: no voltage readings, no temperatures and no balancing for that section. GM therefore puts all of these codes into a fault bundle called BICM Loss of Comm in its 2018 hybrid table, which blocks battery diagnostics that would otherwise misfire on missing values. On the road the controller shields the pack, so reduced power, refused charging or opened contactors are to be expected. Audi bulletin 2078135 for the 2016 A3 Sportback e-tron describes a drive system that cannot be activated and a red warning lamp, with U01A500 among the A-H codes plus P0AA500 and P0A7D00. GM monitors F as Type A from 2016 to 2019.
- What you may notice
- Drive system cannot be activated, red warning lamp
- Charging refused or stopped early
- Other battery diagnostics suspended while the code is active
- Likely causes
- LikelyChain connection between module E and module F interrupted
- PossibleBattery interface control module F defective
- RareBoard F loses supply because its cell group or sense tap is open
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.